1. Field of the Invention
The present invention relates, in general, to an air filter assembly of a blower for vehicles and, more particularly, to an air filter assembly of a blower for vehicles, which is fabricated using a small number of elements, reduces the energy consumption and increases heating efficiency when heating the passenger compartment of a vehicle.
2. Description of the Related Art
Generally, an air conditioner for vehicles heats or cools indoor air inside the passenger compartment of a vehicle or outdoor air, which is atmospheric air, and supplies the heated or cooled air into the passenger compartment, thus controlling the temperature inside the passenger compartment. The air conditioner for vehicles includes an air conditioner casing having therein both a heater core for heating the indoor or outdoor air and an evaporator for cooling the air, and a blower for supplying air into the air conditioner casing.
FIG. 1 is a view illustrating a conventional blower for vehicles. As shown in FIG. 1, the blower 1 for vehicles comprises an intake duct 10 provided both with an indoor air intake port 12 for supplying indoor air and with an outdoor air intake port 11 for supplying outdoor air, and a scroll casing 20 provided therein with a blower fan 22 for forcibly feeding the indoor and outdoor air into the air conditioner casing.
In the intake duct 10, both an indoor and outdoor air control door 13 for selectively opening the outdoor air intake port 11 or the indoor air intake port 12 and an air filter casing 30 receiving an air filter 40 therein are installed. Further, a motor 23 for rotating the blower fan 22 is coupled to the blower fan 22.
When a user selects a heating mode to heat the passenger compartment of a vehicle, the user can select indoor air or outdoor air as the air which is to be fed into the blower 1. When the user selects an outdoor air inlet mode in consideration of an indoor environment of the vehicle, the indoor and outdoor air control door 13 closes the indoor air intake port 12 and opens the outdoor air intake port 11. When the blower fan 22 is operated in the above state, outdoor air is supplied into the intake duct 10 through the outdoor air intake port 11. The inlet outdoor air flows into the scroll casing 20 through the bell mouth 21 of the scroll casing 20 and is forcibly fed into the air conditioner casing.
However, when cool outdoor air is supplied into the air conditioner casing through the outdoor air intake port 11 during the heating mode, an excessive amount of energy must be required to heat the passenger compartment to a desired temperature, thus reducing heating efficiency of the air conditioner.
In an effort to solve the above-mentioned problem, a blower having an improved construction as shown in FIG. 2 through FIG. 4 has been proposed. As shown in FIG. 2 through FIG. 4, the conventional blower having the improved construction is configured such that, during outdoor air inlet mode, in which outdoor air is supplied into the intake duct 10 in the direction of the arrow A, a predetermined amount of indoor air is supplied into the intake duct 10 in the direction of the arrow B through a subsidiary indoor air intake port 51 provided in an air filter casing 50 having an air filter 60 therein and, thereafter, the outdoor air and the indoor air, which have been supplied into the intake duct 10, flow into the scroll casing 20 in respective directions of the arrows C and D and, thereafter, mixed air prepared by the combination of the outdoor air with the indoor air is supplied into the air conditioner casing by a blower fan 22 in the direction of the arrow E.
In the above state, when there is no difference between indoor pressure and outdoor pressure of the intake duct 10, the subsidiary indoor air intake port 51 of the air filter casing 50 is maintained in a closed state by a subsidiary door 70 of the air filter casing 50. However, when there is a difference between the indoor pressure and the outdoor pressure of the intake duct 10, the subsidiary indoor air intake port 51 of the air filter casing 50 is maintained in an open state by the subsidiary door 70 of the air filter casing 50.
However, when the subsidiary door 70 is installed in the air filter casing 50 as described above, the subsidiary door 70 may generate noises because of the interference between the air filter casing 50 and the subsidiary door 70 during operation. In order to remove the noises, a flap 80 is installed on a first side of the subsidiary door 70. Further, a shaking prevention frame 90 is installed on a second side of the subsidiary door 70 so as to remove noises, which may be generated by shaking of the subsidiary door 70.
However, the above-mentioned conventional blower having the improved construction requires an excessive number of elements, thus having a complicated construction and increasing the production costs of vehicles and requiring that a long time be spent assembling the vehicles.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.